New Publication Shows DecisionDx®-SCC Identifies High-Risk Squamous Cell Carcinoma Patients Who Are Likely to Benefit from Adjuvant Radiation Therapy and Those Who Can Consider Deferring Treatment Based on Biological Risk of Metastasis
Castle Biosciences announced a publication demonstrating the efficacy of their DecisionDx-SCC test in identifying high-risk cutaneous squamous cell carcinoma (SCC) patients who benefit from adjuvant radiation therapy (ART). The study, published in the International Journal of Radiation Oncology • Biology • Physics, revealed that patients with Class 2B test results, indicating the highest risk of metastasis, showed a 50% higher metastasis-free survival (MFS) rate when treated with ART compared to those who did not receive ART. Additionally, Class 1 patients, with lower metastatic risk, did not show improved survival with ART, suggesting they can potentially avoid the treatment.
These findings highlight the test's role in guiding clinical decisions regarding ART, thereby optimizing patient care by balancing treatment benefits against side effects.
- DecisionDx-SCC test identifies high-risk SCC patients who would benefit from ART.
- Class 2B patients treated with ART had a 50% higher MFS rate.
- Class 2B patients treated with ART showed significant disease progression deceleration.
- Class 2B patients had nearly five times longer projected time to metastasis when treated with ART.
- Class 1 patients can potentially avoid ART, minimizing exposure to treatment side effects.
- Class 2B patients who did not receive ART showed a peak metastasis rate around two years.
- Patients with high-risk clinicopathologic features but Class 1 results did not benefit from ART.
Insights
The findings from this study reveal important implications for patient care in squamous cell carcinoma (SCC). DecisionDx-SCC is demonstrating clinical utility in stratifying patients more precisely based on their biological risk of metastasis. For patients classified as Class 2B, who are at the highest risk of metastasis, the application of adjuvant radiation therapy (ART) showed a remarkable 50% improvement in metastasis-free survival rates. This suggests that the test can significantly guide treatment decisions and improve patient outcomes.
An intriguing aspect is that patients with high-risk clinical features but classified as Class 1 by the test might avoid unnecessary ART. This avoidance not only spares them from the treatment's side effects but also reduces healthcare costs and resources. From a clinical perspective, these insights could lead to more personalized treatment protocols, reducing overtreatment and focusing resources where they're truly needed.
This publication underlines the efficacy of DecisionDx-SCC in identifying patients who would most benefit from ART, which is a significant development in the field of oncology diagnostics. By identifying Class 2B patients who experience a significant deceleration in disease progression with ART, the test addresses one of the key challenges in cancer treatment: the need for precise and effective risk stratification tools. Moreover, the finding that Class 2B patients treated with ART had nearly five times longer projected time to metastasis compared to those untreated highlights the test's potential in extending patient survival.
From a research perspective, these results reinforce the test’s clinical validity and utility, positioning it as a potentially disruptive technology in oncologic care. The differentiation between Class 1 and Class 2B patients is important because it can help tailor treatment strategies more effectively, thereby optimizing patient outcomes and resource allocation.
For investors, Castle Biosciences' DecisionDx-SCC test presents a strong value proposition. The ability to significantly improve metastasis-free survival rates in high-risk SCC patients underscores the test's market potential and clinical relevance. In financial terms, successful demonstration of clinical utility often translates to increased adoption by healthcare providers, which can drive revenue growth for the company.
Furthermore, the differentiation between patients needing ART and those who can defer it suggests potential cost savings for healthcare systems, which might accelerate payer adoption. Castle Biosciences (Nasdaq: CSTL) stands to benefit from this by capturing a larger share of the oncology diagnostic market. It's worth noting that innovations like DecisionDx-SCC could also attract strategic partnerships or acquisition interest, further enhancing shareholder value.
In the study, patients with DecisionDx-SCC Class 2B test results, predicted to have the highest risk of metastasis by the test, who were treated with adjuvant radiation therapy (ART) had
Patients with Class 1 test results, predicted to have a lower risk of metastasis, did not see an improvement in survival after receiving ART, which together indicates these patients may be able to avoid the treatment
“Radiation may be considered for patients with more aggressive SCC tumors to reduce the risk of the cancer returning once the tumor has been removed through surgery,” said Sarah T. Arron, M.D. Ph.D., lead author and board-certified dermatologist and Mohs surgeon at Peninsula Dermatology in
“The study found that DecisionDx-SCC test results can assist clinicians in making these difficult decisions by identifying which patients are most likely to benefit from the treatment.”
Key findings of the study (n=920 patients) include:
-
The DecisionDx-SCC test identified patients projected to receive the greatest benefit from ART to reduce metastatic disease progression. Patients with a Class 2B (highest metastatic risk) test result who were treated with ART had
50% higher MFS rates, on average, than Class 2B patients who did not receive ART at five years post-diagnosis. - A DecisionDx-SCC Class 2B result was the only independent risk factor that successfully identified patients who would most benefit from ART. Risk factors in the analysis included differentiation status, invasion into fat, perineural invasion and others, including National Comprehensive Cancer Network (NCCN) risk category and Brigham and Women's Hospital and American Joint Committee on Cancer Eighth Edition T-stages.
- Class 2B patients who received ART showed a significant deceleration in disease progression compared to Class 2B patients who did not receive ART. For patients with a DecisionDx-SCC Class 2B test result who were not treated with ART, there was a peak rate of metastasis around two years; Class 2B, ART-treated patients had nearly five times longer projected time to metastasis.
- DecisionDx-SCC identified patients who were less likely to show a significant benefit from ART in controlling disease progression. Patients with high-risk clinicopathologic features but who received a DecisionDx-SCC Class 1 (lower metastatic risk) test result did not show a significant benefit from ART. Given the low risk of metastasis for Class 1 patients, in addition to the lower likelihood of ART benefit, Class 1 patients may consider deferring treatment.
About DecisionDx-SCC
DecisionDx-SCC is a 40-gene expression profile test that uses an individual patient’s tumor biology to stratify risk of metastasis in patients with cutaneous squamous cell carcinoma who have one or more NCCN high-risk factors. The test result, in which patients are stratified into a Class 1 (lower), Class 2A (higher) or Class 2B (highest) risk category, predicts individual metastatic risk to inform risk-appropriate management and guide decision-making regarding the use of adjuvant radiation therapy. Peer-reviewed publications have demonstrated that DecisionDx-SCC is an independent predictor of metastatic risk and that the test can significantly improve risk-stratification when used with traditional staging systems and clinicopathologic risk factors to guide risk-aligned management and treatment decisions. Learn more at www.CastleBiosciences.com.
About Castle Biosciences
Castle Biosciences (Nasdaq: CSTL) is a leading diagnostics company improving health through innovative tests that guide patient care. The Company aims to transform disease management by keeping people first: patients, clinicians, employees and investors.
Castle’s current portfolio consists of tests for skin cancers, Barrett’s esophagus, mental health conditions and uveal melanoma. Additionally, the Company has active research and development programs for tests in other diseases with high clinical need, including its test in development to help guide systemic therapy selection for patients with moderate-to-severe atopic dermatitis, psoriasis and related conditions. To learn more, please visit www.CastleBiosciences.com and connect with us on LinkedIn, Facebook, X and Instagram.
DecisionDx-Melanoma, DecisionDx-CMSeq, DecisionDx-SCC, MyPath Melanoma, DiffDx-Melanoma, TissueCypher, IDgenetix, DecisionDx-UM, DecisionDx-PRAME and DecisionDx-UMSeq are trademarks of Castle Biosciences, Inc.
Forward-Looking Statements
This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, which are subject to the “safe harbor” created by those sections. These forward-looking statements include, but are not limited to, statements concerning: the continued ability of the DecisionDx-SCC test to identify patients with high-risk SCC who would most likely benefit from ART based on the biological risk of metastasis. The words “can,” “may” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements that we make. These forward-looking statements involve risks and uncertainties that could cause our actual results to differ materially from those in the forward-looking statements, including, without limitation: subsequent study or trial results and findings may contradict earlier study or trial results and findings or may not support the results shown in this study, including with respect to the discussion of DecisionDx-SCC in this press release; actual application of our tests may not provide the aforementioned benefits to patients; and the risks set forth under the heading “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2023, our Quarterly Report on Form 10-Q for the quarter ended March 31, 2024 and in our other filings with the SEC. The forward-looking statements are applicable only as of the date on which they are made, and we do not assume any obligation to update any forward-looking statements, except as may be required by law.
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Investor Contact:
Camilla Zuckero
czuckero@castlebiosciences.com
Media Contact:
amarshall@castlebiosciences.com
Source: Castle Biosciences Inc.
FAQ
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